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991.
Kyoungsook Park Kyusam Choi Hyemee Kim Kwangbae Kim Mi Hee Lee Je-Ho Lee Jean Chinock Kim Rim 《Experimental & molecular medicine》2009,41(6):371-380
During carcinogenesis, NF-κB mediates processes associated with deregulation of the normal control of proliferation, angiogenesis, and metastasis. Thus, suppression of NF-κB has been linked with chemoprevention of cancer. Accumulating findings reveal that heat shock protein 90 (HSP90) is a molecular chaperone and a component of the IκB kinase (IKK) complex that plays a central role in NF-κB activation. HSP90 also stabilizes key proteins involved in cell cycle control and apoptosis signaling. We have determined whether the exogenous administration of isoflavone-deprived soy peptide prevents 7,12-dimethylbenz[α]anthracene (DMBA)-induced rat mammary tumorigenesis and investigated the mechanism of action. Dietary administration of soy peptide (3.3 g/rat/day) significantly reduced the incidence of ductal carcinomas (50%), the number of tumors per multiple tumor-bearing rats (49%; P < 0.05), and extended the latency period of tumor development (8.07 ± 0.92 weeks) compared to control diet animals (10.80 ± 1.30; P < 0.05). Our results have further demonstrated that soy peptide (1) dramatically inhibits the expression of HSP90, thereby suppressing signaling pathway leading to NF-κB activation; (2) induces expression of p21, p53, and caspase-3 proteins; and (3) inhibits expression of VEGF. In agreement with our in vivo data, soy peptide treatment inhibited the growth of human breast MCF-7 tumor cells in a dose-dependent manner and induced apoptosis. Taken together, our in vivo and in vitro results suggest chemopreventive and tumor suppressive functions of isoflavone-deprived soy peptide by inducing growth arrest and apoptosis. 相似文献
992.
Ji Ae Lee Ha Yong Song Sung Mi Ju Su Jin Lee Hyung-Joo Kwon Won Sik Eum Sang Ho Jang Soo Young Choi Jinseu Park 《Experimental & molecular medicine》2009,41(9):629-637
Inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) have been known to be involved in various pathophysiological processes such as inflammation. This study was performed to determine the regulatory function of superoxide dismutase (SOD) on the LPS-induced expression of iNOS, and COX-2 in RAW 264.7 cells. When a cell-permeable SOD, Tat-SOD, was added to the culture medium of RAW 264.7 cells, it rapidly entered the cells in a dose-dependent manner. Treatment of RAW 264.7 cells with Tat-SOD led to decrease in LPS-induced ROS generation. Pretreatment with Tat-SOD significantly inhibited LPS-induced expression of iNOS and NO production but had no effect on the expression of COX-2 and PGE2 production in RAW 264.7 cells. Tat-SOD inhibited LPS-induced NF-κB DNA binding activity, IκBα degradation and activation of MAP kinases. These data suggest that SOD differentially regulate expression of iNOS and COX-2 in LPS-stimulated RAW 264.7 cells. 相似文献
993.
Ho Ki Shim Jeoung Yeon Kim Mi Jeong Kim Hee Sun Sim Dae Won Park Jang Wook Sohn Min Ja Kim 《Experimental & molecular medicine》2009,41(10):687-694
Legionella bacterium, an intracellular pathogen of mononuclear phagocytes, causes acute fatal pneumonia, especially in patients with impaired cellular immune responses. Until recently, however, the toll-like receptor (TLR) engagement of bacterial proteins derived from Legionella is uncertain. We previously showed that a 19-kDa highly conserved peptidoglycan-associated lipoprotein (PAL) of Legionella pneumophila induced the PAL-specific B cell and T cell responses in mice. In this study, we observed that the rPAL antigen of L. pneumophila, as an effector molecule, activated murine macrophages via TLR2 and produced proinflammatory cytokines such as IL-6 and TNF-α. In both BALB/c and TLR4-deficient C3H/HeJ mice, pretreatment of macrophages with anti-TLR2 mAb showed severely impaired cytokine production in response to the rPAL. In addition, in vitro the rPAL treatment increased the cell surface expression of CD40, CD80, CD86 and MHC I/II molecules. We further showed that the synthetic CpG-oligodeoxynucleotides (CpG ODN) coadministered with the rPAL enhanced IL-12 and IL-6 production and expression of CD40, CD80 and MHC II compared to the rPAL treatment alone. In conclusions, these results indicate that Legionella PAL might activate macrophages via a TLR2-dependent mechanism which thus induce cytokine production and expression of costimulatory and MHC molecules. 相似文献
994.
Erwin Miña-Díaz 《Constructive Approximation》2009,29(3):421-448
Let φ(z) be an analytic function on a punctured neighborhood of ∞, where it has a simple pole. The nth Faber polynomial F
n
(z) (n=0,1,2,…) associated with φ is the polynomial part of the Laurent expansion at ∞ of [φ(z)]
n
. Assuming that ψ (the inverse of φ) conformally maps |w|>1 onto a domain Ω bounded by a piecewise analytic curve without cusps pointing out of Ω, and under an additional assumption concerning the “Lehman expansion” of ψ about those points of |w|=1 mapped onto corners of ∂
Ω, we obtain asymptotic formulas for F
n
that yield fine results on the limiting distribution of the zeros of Faber polynomials.
相似文献
995.
试论高等学校图书馆建筑的扩建 总被引:1,自引:0,他引:1
作为高校三大支柱之一的大学图书馆,其发展、建设水平非常引人注目。而且在时空的变换下,图书馆建筑还具有变异和扩展的特性。本文试从图书馆建筑扩建的一般特性出发,从以下几个方面作出论证和设想:(1)馆舍的可扩展性;(2)馆舍扩建的模式:(3)借扩建契机,塑造良好的校园文化环境。 相似文献
996.
Transversal Heteroclinic Bifurcation in Hybrid Systems with Application to Linked Rocking Blocks 下载免费PDF全文
In this paper, we study heteroclinic bifurcation and the appearance of chaos in time-perturbed piecewise smooth hybrid systems with discontinuities
on finitely many switching manifolds. The unperturbed system has a heteroclinic orbit connecting hyperbolic saddles of the unperturbed system
that crosses every switching manifold transversally, possibly multiple times. By applying a functional analytical method, we obtain a set of Melnikov
functions whose zeros correspond to the occurrence of chaos of the system. As an application, we present an example of
quasiperiodically excited piecewise smooth system with impacts formed by two linked rocking blocks. 相似文献
997.
George R. Exner Il Bong Jung Mi Ryeong Lee Sun Hyun Park 《Integral Equations and Operator Theory》2014,79(1):49-66
Given the weight sequence for a subnormal recursively generated weighted shift on Hilbert space, one approach to the study of classes of operators weaker than subnormal has been to form a backward extension of the shift by prefixing weights to the sequence. We characterize positive quadratic hyponormality and revisit quadratic hyponormality of certain such backward extensions of arbitrary length, generalizing earlier results, and also show that a function apparently introduced as a matter of convenience for quadratic hyponormality actually captures considerable information about positive quadratic hyponormality. 相似文献
998.
We consider a branching particle system consisting of particles moving according to the Ornstein–Uhlenbeck process in \(\mathbb {R}^d\) and undergoing a binary, supercritical branching with a constant rate \(\lambda >0\) . This system is known to fulfill a law of large numbers (under exponential scaling). Recently the question of the corresponding central limit theorem (CLT) has been addressed. It turns out that the normalization and the form of the limit in the CLT fall into three qualitatively different regimes, depending on the relation between the branching intensity and the parameters of the Ornstein–Uhlenbeck process. In the present paper, we extend those results to \(U\) -statistics of the system, proving a law of large numbers and CLT. 相似文献
999.
设a(z)是一个没有零点的整函数,k≥3是个整数,F是区域D上的亚纯函数族,对每一个f∈F至少有k重零点和2重极点.若对每一对f,g∈F有ff(k)与gg(k)IM分担a(z),则F在区域D内正规. 相似文献
1000.
P. Konarski M. Miśnik L. Dobrzański J. Kozłowski 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(6):1221-1224
Depth profile analysis was performed using two mass spectrometry analytical techniques applying argon ion sputtering—secondary ion mass spectrometry (SIMS) and glow discharge mass spectrometry (GDMS). 150 nm Ni/20 nm Ti/4H-SiC structure was prepared by evaporation coating with titanium and nickel. The structure was analysed as prepared and annealed in 600°C in dry N2. Obtained results allow monitoring several processes present during annealing of Ni/Ti/SiC structures. These are nickel diffusion and its reaction with SiC leading to formation of Ni2Si, precipitation of carbon and segregation of titanium. Results are also used for comparison of the two analytical techniques used. The techniques base on different ionisation mechanisms. In SIMS, secondary ions are formed at the bombarded surface during ion sputtering process in ultra-high vacuum environment, while in GDMS, ionisation occurs in glow discharge above the eroded surface in low vacuum. 相似文献